Along with blood and mucus, he brought up a his left bronchial tree - a series of tubes that distribute air to his lungs.
Doctors aren't quite sure how the clot stayed intact while being coughed up, but Dr Wieselthaler suspects it could be due to the patient's higher level of fibringen in his blood, which acts like a glue.
The patient had a violent coughing fit in hospital a week after surgery to fit him with a pacemaker in case his heart became blocked.
The unnamed man had been admitted to an intensive care unit for chronic heart failure.
According to a case report from the New England Journal of Medicine published on November 29, during a particularly violent coughing spell, the man coughed up his right bronchial tree - all intact. But because these machines can also increase the risk of blood clots, he was prescribed a blood-thinner medication. And, during a rather extreme hack, he coughed up "an intact cast of the right bronchial tree".
Sadly, the patient died from complications of heart failure almost a week later.
"It's a curiosity you can't imagine".
The clot shows the three segmental branches in the upper lobe (white arrows), two segmental branches of the middle lobe (black arrows) and five segmental branches of the lower lobe (blue arrows), the NEJM said.